Firearms, sequential firing systems, and methods

ABSTRACT

Firearms, firing systems, and methods may include a receiver, a double-action firing system, and a barrel assembly. The barrel assembly may include a plurality of barrels, and may be moveable relative to the receiver between a firing position and a loading position. The double-action firing system may be configured to fire one of the plurality of barrels with a first pull of a single trigger, and another of the plurality of barrels with a second pull of the single trigger.

RELATED APPLICATIONS

This non-provisional application incorporates by reference for all purposes the subject matter of provisional application Ser. No. 61/791,226, filed Mar. 15, 2013, entitled “Firearms, Sequential Firing Systems, and Methods”; and provisional application Ser. No. 61/750,738, filed Jan. 9, 2013, entitled “Tactical Pistol Sequential Firing Systems and Methods”.

TECHNICAL FIELD

This application relates generally to the field of firearms. More particularly and without limitation, this application relates to concealable pistols or handguns, and firing systems associated with concealable pistols or handguns.

BACKGROUND

An ongoing need exists for easily concealable firearms for use, for example, in military, law enforcement, and personal defense applications. Given the common usage as a life saving device, such firearms typically benefit from being reliable and from having sufficient power to stop an anticipated threat. For ease of concealment, desirable features for these firearms may include low weight, small size, ease of operation, and a snag-free design for high versatility. However, a problem exists with known firearms in integrating these features and other features into a firearm design that is also reliable, easy to use, and powerful enough to suit the particular application.

SUMMARY

Shortcomings with certain aspects of firearms, firing systems, and methods are addressed as shown and described in a variety of non-limiting, illustrative embodiments herein.

In some embodiments, a firearm may include a receiver, a barrel assembly, a trigger, a first hammer, and a second hammer. The barrel assembly may include a first barrel and a second barrel. The trigger may be moveable between an extended position and a retracted position. The first hammer may be configured to strike a first firing pin with a first movement of the trigger from the extended position to the retracted position. The second hammer may be configured to strike a second firing pin with a second movement of the trigger from the extended position to the retracted position.

In other embodiments, provided is a firing system that may include a camshaft, a first hammer actuation cam, a second hammer actuation cam, a drive cam, a first hammer, and a second hammer. The first hammer actuation cam may be rotatable about the camshaft and may include a plurality of first lobes spaced at a first degree of separation that may be substantially equidistant between each of the first lobes. The second hammer actuation cam may be rotatable about the camshaft and may include a plurality of second lobes spaced at a second degree of separation that may be substantially equidistant between each of the second lobes. The drive cam may be rotatable about the camshaft and may be disposed between the first hammer actuation cam and the second hammer actuation cam. Further, the drive cam may be secured in a fixed position relative to the first and the second hammer actuation cam and may include a plurality of teeth disposed about the drive cam. One of the teeth on the drive cam may be positioned substantially with zero degrees of separation relative to each of the first lobes and each of the second lobes. The first hammer may be adapted to pivot about a fulcrum and may include a first hammer foot adapted to engage the first lobes. The second hammer may be adapted to pivot about the fulcrum and may include a second hammer foot adapted to engage the second lobes.

In other embodiments, provided is a firearm that may include a plurality of barrels and a double-action firing system. The double-action firing system may include a trigger moveable between an extended position and a retracted position. The double-action firing system may be configured to fire one of the barrels with a first movement of the trigger from the extended position to the retracted position and another of the barrels with a second movement of the trigger from the extended position to the retracted position.

In other embodiments, a firearm may include a receiver, a barrel assembly, and a double-action firing system. The receiver may include a breech face, a latch assembly, and a handle. The handle may have a cartridge trap disposed within the handle and configured to receive spare ammunition cartridges. The cartridge trap may be accessible through a trap door pivotally secured to the handle. The spare ammunition cartridges may be releasably secured relative to one another by a loading clip. Further, the handle may have an integral gripping surface disposed thereon. The barrel assembly may be configured to move relative to the receiver between a loading position and a firing position. The barrel assembly may include a first barrel, a second barrel, a barrel lug, a barrel foot, and a barrel hood. The first and the second barrel may each include a barrel chamber. In the loading position, the barrel chamber of each of the first and the second barrel may be removed from the breech face. In the firing position, the barrel chamber of each of the first and the second barrel may be configured to be positioned adjacent the breech face. The first barrel and the second barrel may be positioned substantially parallel to one another. The barrel lug may have a lug aperture configured to slidably accept a pivot pin disposed in the receiver, wherein the barrel assembly may be pivotal about the pivot pin relative to the receiver between the loading position and the firing position. The pivot pin may be retractable from the receiver and the barrel lug for disengaging the barrel assembly from the receiver. The barrel foot may be configured to releasably engage the latch assembly of the receiver when the barrel assembly is in the firing position. The barrel foot may be disengaged from the latch assembly when the barrel assembly is in the loading position. The barrel hood may be configured to engage the breech face of the receiver when the barrel assembly is in the firing position. The barrel hood may be disengaged from the breech face when the barrel assembly is in the loading position. The double-action firing system may be disposed in the receiver and may include a trigger, a first hammer actuation cam, a second hammer actuation cam, a first internal hammer, and a second internal hammer. The trigger may be moveable between an extended position and a refracted position relative to the receiver and may be coupled to a pawl that is moveable with the trigger between the extended position and the retracted position. The first hammer actuation cam may have a first circumference and a plurality of first lobes spaced about the first circumference at a first degree of separation that may be substantially equidistant between each of the first lobes. The second hammer actuation cam may have a second circumference and a plurality of second lobes spaced about the second circumference at a second degree of separation that may be substantially equidistant between each of the second lobes. The second degree of separation may substantially correspond to the first degree of separation and the second lobes may be secured in a fixed position relative to the first lobes at substantially one-half of the first and the second degree of separation. The pawl of the trigger may be configured to rotate each of the first and the second hammer actuation cam relative to the receiver when the trigger moves from the extended position to the retracted position. The first internal hammer may have a first free end pivotal about a first secured end. The first free end may have a first hammer face configured to strike a first firing pin positioned in the breech face with a first movement of the trigger from the extended position to the retracted position. The first secured end may have a first hammer foot configured to move from a first position engaged with one of the first lobes to a second position disengaged from the first lobe in the first movement of the trigger. When the first hammer foot is in the first position, the first hammer face may be in a resting position near the first firing pin. When the first hammer foot is in the second position, the first hammer face may be released from a cocked position that is spring-biased toward the resting position and the first firing pin. The second internal hammer may have a second free end pivotal about a second secured end. The second free end may have a second hammer face configured to strike a second firing pin positioned in the breech face with a second movement of the trigger from the extended position to the retracted position. The second secured end may have a second hammer foot configured to move from a first position engaged with one of the second lobes to a second position disengaged from the second lobe in the second movement of the trigger. When the second hammer foot is in the first position, the second hammer face may be in a resting position near the second firing pin. When the second hammer foot is in the second position, the second hammer face may be released from a cocked position that is spring-biased toward the resting position and the second firing pin.

Other aspects, features, and advantages of the illustrative embodiments will become apparent with reference to the drawings and detailed description that follow.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of this disclosure may be obtained by reference to the following detailed description when taken in conjunction with the accompanying drawings, forming a part hereof. The drawings are provided for illustrative purposes and without limitation to the scope of the subject matter herein. Further, the drawings are not necessarily to scale, and in some instances, various features may be shown exaggerated or enlarged to facilitate an understanding of the technology. In the drawings, like reference characters generally refer to like features having similar structure or functionality.

FIG. 1A is a left side view of an illustrative embodiment of a pistol that may include a firing system according to this disclosure.

FIG. 1B is a right side view of the pistol depicted in FIG. 1A.

FIG. 2 is a front view of the pistol depicted in FIG. 1A.

FIG. 3 is a top view of the pistol depicted in FIG. 1A.

FIG. 4 is a perspective view of an illustrative embodiment of a barrel assembly of the pistol depicted in FIG. 1A.

FIG. 5A is a perspective view of the pistol of FIG. 1A from the front, depicting an illustrative embodiment of a barrel assembly in a loading position.

FIG. 5B is a perspective view of the pistol of FIG. 1A from the rear, depicting an illustrative embodiment of a barrel assembly in a loading position.

FIG. 6A is a side, partial sectional view of the pistol of FIG. 2, taken at line 6A-6A, and depicting an illustrative embodiment of a firing system according to this disclosure.

FIG. 6B is a detail view of the firing system as shown in FIG. 6A.

FIG. 7A is a perspective view illustrating the firing system depicted in FIGS. 6A-6B.

FIG. 7B is a cross-section view of an illustrative embodiment of a firing pin housing in FIG. 7A, taken at line 7B-7B, and depicting an illustrative embodiment of a cartridge tensioner.

FIG. 8 is a perspective, partial exploded view of the pistol of FIG. 1A, depicting an illustrative embodiment of a barrel assembly and firing pin housings.

FIG. 9A is a left side perspective view of the pistol of FIG. 1A, depicting an illustrative embodiment of a trap door having an adjustable retaining member and being positioned to accept a loading clip.

FIG. 9B is a right side perspective view of the trap door of FIG. 9A having the adjustable retaining member and being positioned to accept the loading clip.

FIG. 9C is a perspective view of the adjustable retaining member depicted in FIGS. 9A and 9B.

FIG. 9D is a cross-section view of the adjustable retaining member of FIG. 9C taken and line 9D-9D.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In the following detailed description of non-limiting, illustrative embodiments, reference is made to the accompanying drawings that form a part hereof. Other embodiments may be utilized, and logical, structural, mechanical, electrical, and chemical changes may be made without departing from the scope of this description. The description may omit certain information known to those skilled in the art. The following detailed description is provided without limitation and with the scope of the illustrative embodiments being defined by the appended claims.

In general, the following illustrative embodiments provide apparatuses, systems, and methods relating to a firearm that may have more than one barrel, and a firing system that may be configured to sequentially fire an ammunition cartridge disposed in each barrel by successive pulls of a single trigger. As described herein, some embodiments of the firing system may include an internal hammer that is cocked or otherwise biased against a biasing mechanism, such as a spring, and subsequently released by each trigger pull, thereby providing a double-action and a double-strike capability. In this manner, the internal hammer may be adapted to strike an ammunition cartridge by each successive pull of the trigger, permitting an operator to strike the cartridge multiple times should the cartridge fail to fire. The illustrative embodiments of the firing system described herein may be particularly suited for firearms having more than one barrel, as indicated above. However, the firing system is not limited to a particular type of firearm, and may be utilized on firearms having, for example, a single barrel. As a further example, the firing system may be utilized in pistols, rifles, shotguns, and other types of firearms. The following illustrative embodiments depict the firing system in the context of a small, lightweight pistol that may be particularly suited for concealment.

Referring generally to FIGS. 1A-7A, depicted is an illustrative embodiment of a firearm, such as a pistol 100, including a firing system 102. The firing system 102 may be a double-action firing system 104, as described below. The pistol 100 may additionally include a receiver 108 and a barrel assembly 112. The receiver 108 may house the double-action firing system 104, and may carry the barrel assembly 112 in a pivotal relationship relative to the receiver 108. The pistol 100 and the double-action firing system 104 may be operated to permit sequential firing through successive pulls of a trigger 116. The trigger 116 may be a single trigger.

Referring to FIGS. 6A-7A, the double-action firing system 104 may include the trigger 116 slidably disposed in a trigger guide 118 provided in the receiver 108. For example, the trigger guide 118 may be, without limitation, a channel, slot, or keyway that is cast, machined, or cut into the substrate material of the receiver 108, and sized to slidably accept the trigger 116. In other embodiments, the channel, slot, or keyway may be a separate component configured to be coupled to the receiver 108 for providing the trigger guide 118. Further, in other embodiments, the trigger 116 may be pivotal relative to the receiver 108.

Within the trigger guide 118, the trigger 116 may be biased to a first position or extended position 120 and retractable to a second position or retracted position 122 for firing the pistol 100 as described herein. For example, the trigger 116 may be biased to the extended position 120 by a biasing mechanism, such as, for example, a trigger spring 124 positioned between the receiver 108 and the trigger 116. The trigger spring 124 may, for example, be disposed in or about a trigger spring guide 126. The trigger spring guide 126 may be formed as a part of the receiver 108, a part of the trigger 116, a separate part, or any suitable combination of the foregoing. As shown in FIGS. 6A-7A, the trigger spring guide 126 may be, without limitation, a pin coupled to the trigger 116 that is sized to be slidably received within a guide port 128 in the receiver 108. The trigger spring 124 may be disposed about the trigger spring guide 126 and positioned between the trigger 116 and a trigger spring seat 130 that may be formed around an entrance to the guide port 128. The trigger spring seat 130 may be any feature configured to permit the trigger spring guide 126 to be slidably received within the guide port 128 while substantially precluding the trigger spring 124 from entering the guide port 128.

The trigger 116 may be coupled to a trigger link 132 that may include a pawl 134 disposed on a distal end 136 of the trigger link 132. The trigger link 132 and the pawl 134 may be moveable with the trigger 116 from the extended position 120 to the retracted position 122. A proximal end 138 of the trigger link 132 may be coupled in a pivotal relationship to the trigger 116. A trigger link spring 140 may be positioned between the trigger 116 and a portion of the trigger link 132 between the proximal end 138 and the distal end 136 of the trigger link 132. The trigger link spring 140 may bias the trigger link 132 and the pawl 134 into engagement with the double-action firing system 104.

Continuing with FIGS. 6A-7A, the double-action firing system 104 may additionally include a first hammer actuation cam 150, a second hammer actuation cam 152, and a drive cam 154. The drive cam 154 may be positioned between the first hammer actuation cam 150 and the second hammer actuation cam 152 on a camshaft 156 that may be disposed in the receiver 108. Further, the first hammer actuation cam 150, the second hammer actuation cam 152, and the drive cam 154 may be secured together in a fixed position and rotatable about the camshaft 156 relative to the receiver 108. In some embodiments, the camshaft 156 may be rotatable relative to the receiver 108 along with the first hammer actuation cam 150, the second hammer actuation cam 152, and the drive cam 154.

The first hammer actuation cam 150, the second hammer actuation cam 152, and the drive cam 154 may be oriented at a fixed position relative to one another. The first hammer actuation cam 150 may include at least one first lobe 158, and the second hammer actuation cam 152 may include at least one second lobe 160. As illustrated in FIGS. 6A-7A, in some embodiments, the first hammer actuation cam 150 may include three of the first lobes 158 spaced substantially equal about 120 degrees apart from one another about a first circumference 162 of the first hammer actuation cam 150. Similarly, the second hammer actuation cam 152 may include three of the second lobes 160 spaced substantially equal about 120 degrees apart from one another about a second circumference 164 of the second hammer actuation cam 152. Also as illustrated in FIGS. 6A-7A, the drive cam 154 may include a plurality of teeth 166. As shown, the drive cam 154 may include six of the teeth 166 spaced substantially equal about 60 degrees apart from one another about a drive cam circumference 170 of the drive cam 154. In this embodiment, the first lobes 158 of the first hammer actuation cam 150 may be fixed with about 60 degrees of separation relative to the second lobes 160 of the second hammer actuation cam 152. Further, one of the teeth 166 of the drive cam 154 may be fixed or positioned substantially in phase, with about zero degrees of separation, relative to each of the first lobes 158 and each of the second lobes 160. Thus, the first lobes 158 may be positioned out of phase from the second lobes 160 by about half the degree of separation of the first lobes 158 on the first hammer actuation cam 150 and the second lobes 160 on the second hammer actuation cam 152. Further, the number of the teeth 166 on the drive cam 154 may be twice the number of the first lobes 158 of the first hammer actuation cam 150, and twice the number of the second lobes 160 of the second hammer actuation cam 152.

In other embodiments, the number of the first lobes 158, the number of the second lobes 160, and the number of the teeth 166 may be increased or decreased proportionally to the embodiment of FIGS. 6A-7A. For example, other embodiments may include four of the teeth 166 spaced substantially equal on the drive cam 154, two of the first lobes 158 spaced substantially equal on the first hammer actuation cam 150, and two of the second lobes 160 spaced substantially equal on the second hammer actuation cam 152. Increasing or decreasing the number of the first lobes 158 on the first hammer actuation cam 150, the second lobes 160 on the second hammer actuation cam 152, and the teeth 166 on the drive cam 154 may modify the timing of fire for the pistol 100.

Continuing with FIGS. 6A-7A, the double-action firing system 104 may additionally include a first internal hammer 180, a second internal hammer 182, a first firing pin 184, and a second firing pin 186. The first internal hammer 180 may have a first hammer foot 188 and a first hammer face 190. Similarly, the second internal hammer 182 may have a second hammer foot 192 and a second hammer face 194. The first hammer face 190 may be superimposed above the second hammer face 194. For example, the first hammer face 190 may be positioned above and substantially in vertical alignment with the second hammer face 194. As further described below, the first lobes 158 of the first hammer actuation cam 150 may be adapted to engage the first hammer foot 188, and the second lobes 160 of the second hammer actuation cam 152 may be adapted to engage the second hammer foot 192. Further, the first hammer face 190 may be adapted to strike the first firing pin 184, and the second hammer face 194 may be adapted to strike the second firing pin 186.

The first internal hammer 180 and the second internal hammer 182 may each be pivotally disposed in the receiver 108 such that the first internal hammer 180 and the second internal hammer 182 are independently pivotal relative to one another and relative to the receiver 108. For example, the first internal hammer 180 may be configured as a lever having a first free end 196 adapted to pivot about a first secured end 198. Similarly, the second internal hammer 182 may be configured as a lever having a second free end 202 adapted to pivot about a second secured end 204. The first secured end 198 and the second secured end 204 may each be secured, for example, in a pivotal manner about a hammer pin 206 positioned in the receiver 108 such that the first free end 196 and the second free end 202 pivot about the hammer pin 206. The first hammer foot 188 may be positioned at or extending from the first secured end 198 of the first internal hammer 180, and the second hammer foot 192 may be positioned at or extending from the second secured end 204 of the second internal hammer 182. Further, the first hammer face 190 may be positioned at the first free end 196 of the first internal hammer 180, and the second hammer face 194 may be positioned at the second free end 202 of the second internal hammer 182. The hammer pin 206 may provide a fulcrum between the first hammer face 190 and the first hammer foot 188, and similarly, between the second hammer face 194 and the second hammer foot 192. In some embodiments, the first hammer face 190 and the first hammer foot 188 may pivotally extend from the fulcrum, and similarly, the second hammer face 194 and the second hammer foot 192 may pivotally extend from the fulcrum.

Referring to FIGS. 5A-8, a firing pin housing 220 may be separately positioned in the receiver 108, or formed from the substrate material of the receiver 108, and configured to orient the first firing pin 184 and the second firing pin 186 for firing ammunition cartridges 222 in the barrel assembly 112. In some embodiments, the firing pin housing 220 may carry both the first firing pin 184 and the second firing pin 186. In other embodiments, as shown in FIGS. 5A-8, the firing pin housing 220 may include a first firing pin housing 220 a and a separate second firing pin housing 220 b configured to be disposed in a breech face 224 on the receiver 108. The first firing pin housing 220 a and the second firing pin housing 220 b may form a portion of the breech face 224. The first firing pin housing 220 a may carry the first firing pin 184 and may be positioned in the receiver 108 substantially parallel to the second firing pin housing 220 b that may carry the second firing pin 186. In other embodiments, the first hammer face 190 and the second hammer face 194 may each carry a firing pin configured to momentarily protrude through a portion of the breech face 224 on the receiver 108 for firing the ammunition cartridges 222 in the barrel assembly 112.

The first firing pin housing 220 a and the second firing pin housing 220 b may each have a cartridge support surface 230, a housing body 232, and a housing base 234. As shown in FIGS. 6A-8, the housing body 232 of each of the first firing pin housing 220 a and the second firing pin housing 220 b may have a substantially cylindrical interior and exterior shape. However, other shapes are possible. The cartridge support surface 230 and the housing base 234 may be longitudinally disposed from one another and positioned at opposite ends of the housing body 232 of each of the first firing pin housing 220 a and the second firing pin housing 220 b. The cartridge support surface 230 of each of the first firing pin housing 220 a and the second firing pin housing 220 b may have a firing pin hole 236 disposed through the cartridge support surface 230. The housing base 234 of each of the first firing pin housing 220 a and the second firing pin housing 220 b may have a housing base opening 238 disposed through the housing base 234. The firing pin hole 236 in the cartridge support surface 230 may be substantially concentric to the housing base opening 238 in the housing base 234.

Referring to FIGS. 6A-6B, the first firing pin 184 may be slidable within the first firing pin housing 220 a, and the second firing pin 186 may be slidable within the second firing pin housing 220 b. The first firing pin 184 and the second firing pin 186 may each have a firing pin tip 242 and a firing pin base 244. The firing pin tip 242 and the firing pin base 244 may be positioned at opposite ends of each of the first firing pin 184 and the second firing pin 186. The firing pin tip 242 of the first firing pin 184 may be configured to protrude through the firing pin hole 236 of the first firing pin housing 220 a to strike and discharge one of the ammunition cartridges 222. Similarly, the firing pin tip 242 of the second firing pin 186 may be configured to protrude through the firing pin hole 236 of the second firing pin housing 220 b to strike and discharge another of the ammunition cartridges 222. In a resting state shown in FIGS. 6A-6B, the firing pin base 244 of each of the first firing pin 184 and the second firing pin 186 may be biased to protrude through the housing base opening 238. Also in the resting state, the firing pin tip 242 of each of the first firing pin 184 and the second firing pin 186 may be positioned at or below the cartridge support surface 230. The first firing pin 184 and the second firing pin 186 may each be biased to the resting state with the firing pin base 244 positioned toward and protruding through the housing base opening 238 by a firing pin spring 246, for example.

The first firing pin 184 and the second firing pin 186 may have any size or shape to suit a particular application. Further, the first firing pin 184 may have a different size or shape than the second firing pin 186. The firing pin spring 246 operable on the first firing pin 184 may have the same or a different spring rate from the firing pin spring 246 operable on the second firing pin 186. The first firing pin 184 and the second firing pin 186 may be driven at different velocities by modifying features such as, for example, the size and shape of the first firing pin 184 and the second firing pin 186, and the spring rate of the firing pin spring 246.

Referring to FIGS. 5A-8, the cartridge support surface 230 and the firing pin hole 236 of each of the first firing pin housing 220 a and the second firing pin housing 220 b may be positioned in the receiver 108 facing the barrel assembly 112 and the ammunition cartridges 222. Further, the housing base 234 and the housing base opening 238 of the first firing pin housing 220 a may be positioned in the receiver 108 facing the first hammer face 190. Similarly, the housing base 234 and the housing base opening 238 of the second firing pin housing 220 b may be positioned in the receiver 108 facing the second hammer face 194. In this manner, the first hammer face 190 may be positioned to strike the firing pin base 244 of the first firing pin 184, and the second hammer face 194 may be positioned to strike the firing pin base 244 of the second firing pin 186.

The first firing pin housing 220 a and the second firing pin housing 220 b, may be coupled to the receiver 108 in any suitable manner. Further, the first firing pin housing 220 a and the second firing pin housing 220 b may be releasably secured within the breech face 224 of the receiver 108 to permit servicing or replacement without disassembly of the pistol 100. For example, in some embodiments, the first firing pin housing 220 a and the second firing pin housing 220 b may be threaded into the receiver 108. In other embodiments, as shown in FIGS. 6A-8, the first firing pin housing 220 a may be configured to be inserted into a first cavity 250 within the breech face 224 of the receiver 108, and the second firing pin housing 220 b may be configured to be inserted into a second cavity 252 in the breech face 224. The receiver 108 may include a keyway 254 or opening disposed through at least a portion of the receiver 108 and positioned to intersect at least a portion of both the first cavity 250 and the second cavity 252. The keyway 254 may be sized and configured to accept a locking key 256. The first firing pin housing 220 a may carry a first recess 260 on an first housing exterior 262 or circumference of the first firing pin housing 220 a, and the second firing pin housing 220 b may carry a second recess 264 on a second housing exterior 266 or circumference of the second firing pin housing 220 b.

Continuing with FIGS. 6A-8, with the first firing pin housing 220 a fully inserted into the first cavity 250 and the second firing pin housing 220 b fully inserted into the second cavity 252, the first recess 260 and the second recess 264 may be substantially aligned on the keyway 254 and configured to engage the locking key 256. Further, when the first firing pin housing 220 a and the second firing pin housing 220 b are fully inserted as described above, the first recess 260 and the second recess 264 may define at least a portion of the keyway 254 configured to accept the locking key 256. In this manner, the locking key 256 may be configured to engage the first recess 260 and the second recess 264 in the keyway 254 for securing the first firing pin housing 220 a and the second firing pin housing 220 b to the receiver 108. Although FIGS. 6A-6B and 8 depict the keyway 254 and the locking key 256 as having a substantially circular cross section, other shapes are possible.

In some embodiments, the locking key 256 may include a fastening aperture 270 and a locking key spring clip 272. The fastening aperture 270 may be disposed into or through the locking key 256 and sized to receive a fastener 274, such as a screw or pin, for securing the locking key 256 to the keyway 254 of the receiver 108. As shown in FIGS. 6A-6B and 8, the fastening aperture 270 may be disposed through the longitudinal length of the locking key 256 and configured permit the fastener 274 to pass through the locking key 256 for engaging a threaded portion 276, shown in FIG. 1B, on an opposite side of the receiver 108.

The locking key spring clip 272 may be positioned in or around at least a portion of a locking key channel 278 or groove in the external surface, or locking key exterior 280, of the locking key 256. The locking key spring clip 272 may be a flexible metal wire or similar structure configured to provide tension when compressed within the keyway 254. For example, the locking key spring clip 272 may be substantially compressed below the locking key exterior 280 of the locking key 256 within the locking key channel 278 when the locking key 256 is positioned within the keyway 254. The locking key spring clip 272 may expand above the locking key exterior 280 of the locking key 256 when removed from the keyway 254. Thus, when positioned within the keyway 254, the locking key spring clip 272 may be configured to provide tension among the receiver 108, the first firing pin housing 220 a, and the second firing pin housing 220 b. For example, the locking key spring clip 272 may be positioned on the locking key 256 to engage portions of the first recess 260, the second recess 264, and the receiver 108 when the locking key 256 is inserted in the keyway 254. The tension provided by the locking key spring clip 272 may reduce movement or float of the first firing pin housing 220 a and the second firing pin housing 220 b relative to the receiver 108. In some embodiments, the fastening aperture 270 and the locking key spring clip 272 may be used independently of one another to secure the locking key 256 within the keyway 254.

Referring to FIGS. 5A-5B and 7A-7B, the first firing pin housing 220 a and the second firing pin housing 220 b may each include at least one cartridge tensioner 290. The cartridge tensioner 290 may be configured to urge the ammunition cartridges 222 into position within the barrel assembly 112, and to substantially prevent movement of the ammunition cartridges 222 therein. The cartridge tensioner 290 may be positioned in the cartridge support surface 230 of each of the first firing pin housing 220 a and the second firing pin housing 220 b. For example, as shown in FIG. 7A, two of the cartridge tensioners 290 may be positioned in the cartridge support surface 230 substantially equidistant about a circumference of the firing pin hole 236. The cartridge tensioner 290 may be configured to engage a cartridge head 294 of the ammunition cartridges 222 to bias the ammunition cartridges 222 into alignment within the barrel assembly 112. The configuration of the cartridge tensioner 290 may enhance reliability and ignition by supporting the ammunition cartridges 222 at a consistent distance and position relative to the firing pin hole 236. In other embodiments, the number of the cartridge tensioners 290 may be increased or decreased to suit a particular application. Further, the cartridge tensioner 290 may be positioned at the breech face 224 of the receiver 108 in any suitable location that permits the cartridge tensioner 290 to engage the cartridge head 294 of the ammunition cartridges 222 as described herein.

The cartridge tensioner 290 may include a tensioning projection 302 held captive by a tensioner detent 306, or other retaining element. The tensioning projection 302 and the tensioner detent 306 may be positioned to face the barrel assembly 112 and the ammunition cartridges 222 disposed therein. Further, the cartridge tensioner 290 may include a tensioner bore 310 and a tensioner biasing spring 314. The tensioning projection 302 may be, for example, a metal ball having a substantially spherical shape. However, in other embodiments, the tensioning projection 302 may be formed of other rigid materials and may have other suitable shapes. The tensioner detent 306 may be, for example, a hole or aperture in the cartridge support surface 230 or the breech face 224 having a diameter or size that is less than a diameter or size of the tensioning projection 302. Accordingly, the tensioner detent 306 may be sized or otherwise configured to permit a portion of the tensioning projection 302 to partially protrude through the tensioner detent 306 and above the cartridge support surface 230 or the breech face 224 without permitting the tensioning projection 302 to fully pass through the tensioner detent 306.

The tensioning projection 302 and the tensioner biasing spring 314 may be positioned in the tensioner bore 310 and moveable within the tensioner bore 310. The tensioner bore 310 may be, for example, a hole, such as a cylindrically shaped hole, machined or formed into the breech face 224 or the cartridge support surface 230. The tensioner detent 306 may be coupled to an end of the tensioner bore 310 facing the barrel assembly 112 and the ammunition cartridges 222 for retaining the tensioning projection 302 and the tensioner biasing spring 314 in the tensioner bore 310. The tensioning projection 302 may be positioned between the tensioner detent 306 and the tensioner biasing spring 314 such that the tensioning projection 302 is spring biased toward the tensioner detent 306 and held captive by the tensioner detent 306 with a portion of the tensioning projection 302 being positioned above the cartridge support surface 230 and the breech face 224. The tensioning projection 302 may be retractable within the tensioner bore 310 below the cartridge support surface 230 and the breech face 224 against the spring bias provided by the tensioner biasing spring 314. In this manner, the tensioning projection 302 of the cartridge tensioner 290 may be configured to engage the cartridge head 294 of the ammunition cartridges 222. When engaged with the ammunition cartridges 222, the tensioning projection 302 may be configured to exert the spring bias of the tensioner biasing spring 314 upon the ammunition cartridges 222 for supporting the ammunition cartridges 222.

Referring to FIGS. 6A-7A, the first internal hammer 180 may be biased toward the first firing pin 184 and the second internal hammer 182 may be biased toward the second firing pin 186 by at least one hammer spring 320. The hammer spring 320 may be positioned between the receiver 108 and the first free end 196 of the first internal hammer 180 and the second free end 202 of the second internal hammer 182. As shown in FIG. 7A, the at least one hammer spring 320 may be a first hammer spring 320 a and a second hammer spring 320 b. The first hammer spring 320 a may be configured to bias the first internal hammer 182 and the first hammer face 190 toward the first firing pin 184. Similarly, the second hammer spring 320 b may be configured to bias the second internal hammer 182 and the second hammer face 194 toward the second firing pin 186. The hammer spring 320, the first hammer spring 320 a, and the second hammer spring 320 b may be any suitable spring, such as, for example, a leaf spring, a leaf spring having a taper and a u-shape, a torsion spring, a compression spring, or an omega spring. Further, the hammer spring 320, the first hammer spring 320 a, and the second hammer spring 320 b may be a single spring or multiple springs having the same or different spring rates. In some embodiments, the hammer spring 320 may be a single spring operable on both the first internal hammer 180 and the second internal hammer 180.

Continuing with FIGS. 6A-7A, the teeth 166 of the drive cam 154 may engage the pawl 134 such that the movement of the trigger 116 to the refracted position 122 may impart rotation of the first lobes 158 and the second lobes 160 relative to the receiver 108. The movement of the trigger 116 to the refracted position 122 may engage one of the first lobes 158 with the first hammer foot 188 or one of the second lobes 160 with the second hammer foot 192. For example, for the orientation depicted in FIGS. 6A-6B, counter-clockwise rotation of the first hammer actuation cam 150 may cause one of the first lobes 158 to engage the first hammer foot 188, imparting rotation of the first internal hammer 180 about the hammer pin 206 against the spring bias of the first hammer spring 320 a. In this manner, the first internal hammer 180 may move away from a resting position near the first firing pin 184 and toward a cocked position as shown in FIGS. 6A-7A. Continued movement of the trigger 116 to the retracted position 122 may cause the first lobe 158 to disengage from the first hammer foot 188 when the first internal hammer 180 has reached the cocked position. When the first lobe 158 disengages from the first hammer foot 188, the first internal hammer 180 may fall such that the first hammer face 190 strikes the first firing pin 184 causing the first firing pin 184 to temporarily protrude through the firing pin hole 136 for igniting the ammunition cartridges 222.

After the first internal hammer 180 falls to discharge the pistol 100 as described above, the trigger 116 may be released or otherwise reset to the extended position 120 to prepare the pistol 100 to fire a second time. At this stage of fire, movement of the trigger 116 to the refracted position 122 a second time may, for the orientation of FIG. 7A, impart clockwise rotation of the second hammer actuation cam 152. Rotation of the second hammer actuation cam 152 may cause one of the second lobes 160 to engage the second hammer foot 192, imparting rotation of the second internal hammer 182 about the hammer pin 206 against the spring bias of the second hammer spring 320 b. In this manner, similar in operation to the first internal hammer 180, the second internal hammer 182 may move away from a resting position near the second firing pin 186, shown in FIGS. 6A-7A, and toward a cocked position. Continued movement of the trigger 116 to the refracted position 122 may cause the second lobe 160 to disengage from the second hammer foot 192 when the second internal hammer 182 has reached the cocked position. When the second lobe 160 disengages from the second hammer foot 192, the second internal hammer 182 may fall such that the second hammer face 194 strikes the second firing pin 186 causing the second firing pin 186 to temporarily protrude through the firing pin hole 136 for igniting another of the ammunition cartridges 222.

As described above, each movement of the trigger 116 to the retracted position 122 may move the first internal hammer 180 or the second internal hammer 182 to the cocked position, and subsequently release the first internal hammer 180 to strike the first firing pin 184 or the second internal hammer 182 to strike the second firing pin 186 for firing the pistol 100. The trigger 116 may be reset or otherwise allowed to move back to the extended position 120 to prepare the pistol 100 to fire a second time. However, in other embodiments, the number and the degree of separation between the first lobes 158 of the first hammer actuation cam 150 and the second lobes 160 of the second hammer actuation cam 152 may be modified to change the timing and sequence of fire provided by the double-action firing system 104. For example, the first internal hammer 180 and the second internal hammer 180 may be configured to fall simultaneously with a single pull of the trigger 116. In such a configuration, the first lobes 158 and the second lobes 160 may be fixed with about zero degrees of separation relative to one another to cause both the first internal hammer 180 and the second internal hammer 182 to fall simultaneously with a single pull of the trigger 116. Further, the first internal hammer 180 and the second internal hammer 182 may be configured to fall sequentially, the second internal hammer 182 after the first internal hammer 180, with a single pull of the trigger 116. For example, the first lobes 154 and the second lobes 160 may be increased in number or fixed with less degree of separation relative to one another such that a single pull of the trigger 116 may cause one of the second lobes 160 to engage the second hammer foot 192 after one of the first lobes 158 engages the first hammer foot 188. Thus, increasing the number of the first lobes 158 and the second lobes 160 and decreasing the respective degree of separation between the first lobes 158 and the second lobes 160 may cause the first internal hammer 180 and the second internal hammer 182 to be released closer together temporally. Such a modification may require a proportional increase in the number of teeth 166 on the drive cam 154, and may also shorten the length of movement of the trigger 116 from the extended position 120 to the retracted position 122.

Further, the contact surfaces between first lobes 158 and the first hammer foot 188, and the contact surfaces between the second lobes 160 and the second hammer foot 192 may have any suitable shape facilitating disengagement as described above when the first internal hammer 180 and the second internal hammer 182 are in the cocked position. The contact surfaces may also be modified to change the timing of the disengagement, and thus, the timing of the discharge of the pistol 100. Even further, the contact surfaces described above, the diameter of the drive cam 154, and the diameter of each of the first hammer actuation cam 150 and the second hammer actuation cam 152 may be modified to provide a desired trigger pull weight, or force required to move the trigger 116 from the extended position 120 to the retracted position 122.

Referring to FIGS. 1A-1B and 5A-7A, the double-action firing system 104 may be operable on the barrel assembly 112 for igniting the ammunition cartridges 222 disposed in the barrel assembly 112. For example, when the barrel assembly 112 is in a firing position shown in FIGS. 1A-1B, the ammunition cartridges 222 shown in FIG. 5B may be positioned adjacent the breech face 224. When adjacent the breech face 224, the ammunition cartridges 222 may be substantially aligned with the first firing pin 184 and the second firing pin 186 such that the double-action firing system 104 may ignite the ammunition cartridges 222 as described herein.

Referring to FIGS. 1-6B, the barrel assembly 112 may have an over-under, double-barrel configuration including a first barrel 330 and a second barrel 332 positioned substantially parallel relative to one another. The first barrel 330 may be positioned vertically above the second barrel 332 with the pistol 100 oriented in the firing position depicted in FIGS. 1A-1B, for example. The first barrel 330 and the second barrel 332 may each have a barrel chamber 336 and a muzzle 338. Each barrel chamber 336 may be positioned at an opposite end of the barrel assembly 112 from the muzzle 338. Further, each barrel chamber 336 may be sized, burnished, or polished as appropriate to receive the ammunition cartridges 222.

In other embodiments, the first barrel 330 and the second barrel 332 may be positioned side-by-side in a substantially horizontal configuration when the pistol 100 is in the firing position. Further, the number of barrels in the barrel assembly 112 may be increased or decreased to suit a particular application, and thus, the double-action firing system 104 may be adapted to fire a different number of barrels than provided in the illustrative embodiments herein.

Referring to FIGS. 4-6B and 8, the barrel assembly 112 may additionally include a barrel lug 342 and a barrel foot 344. The barrel lug 342 and the barrel foot 344 may be configured to be positioned between the barrel assembly 112 and the receiver 108. The barrel lug 342 may have a lug aperture 346 sized to slidably accept a retaining member, such as a pivot pin 348, that may be disposed in the receiver 108. The barrel assembly 112 may be configured to pivot relative to the receiver 108 about an axis defined by the pivot pin 348. The pivot pin 348 may be releasably retained in the receiver 108 by a pivot pin spring clip 350.

The pivot pin spring clip 350 may be positioned in or around at least a portion of a pivot pin channel 354, such as a groove in the external surface, or pivot pin exterior 356, of the pivot pin 348. The pivot pin spring clip 350 may be a flexible metal wire or similar structure configured to provide tension when compressed. For example, the pivot pin spring clip 350 may be substantially compressed below the pivot pin exterior 356 within the pivot pin channel 354 when the pivot pin 348 is positioned within the lug aperture 346 and the receiver 108. The pivot pin spring clip 350 may be biased to expand above the pivot pin exterior 356 when removed from the lug aperture 346 and the receiver 108. Thus, the pivot pin spring clip 350 may provide tension or interference among the pivot pin 348, the lug aperture 346, and the receiver 108 for retaining the pivot pin 348 in the receiver 108. In this manner, the pivot pin 348 may be refracted or disengaged from, for example, a side of the receiver 108 and the lug aperture 346 for removing the barrel assembly 112 from the receiver 108 without tools. In other embodiments, the pivot pin 348 may be releasably retained by other suitable devices capable of providing interference between the pivot pin 348 and the receiver 108.

Referring to FIGS. 1A-1B and 5A-6B, the barrel foot 344 may be adapted to engage a latch assembly 360 carried by or disposed in the receiver 108. The latch assembly 360 may include a latch tab 362 on a side of the receiver 108 that is operable on a latch pin 364 adapted to capture the barrel foot 344 when the barrel assembly 112 is pivoted toward the receiver 108 and into the firing position shown in FIGS. 1A-1B. The latch tab 362 may be, for example, a set of ambidextrous, thumb-actuated tabs slidable on each side of the receiver 108. The latch pin 364 may be moveable within a latch pin channel 368 disposed in the receiver 108 between a latching or extended position and a releasing or retracted position. The latch tab 362 may be coupled to the latch pin 364 from the exterior of the receiver 108 such that the latch tab 362 is moveable with the latch pin 364 between the extended position and the retracted position. Further, the latch pin 364 may be biased by a latch spring 372, or similar biasing member, to the extended position where the latch pin 364 may be positioned in the receiver 108 to engage the barrel foot 344. The latch spring 372 may be positioned in the latch pin channel 368 between the receiver 108 and the latch pin 364 for biasing the latch pin 364 to the extended position. Further, the latch spring 372 may be disposed about a latch spring guide member 374 coupled to the latch pin 364, for example, to prevent binding of the latch spring 372 within the latch pin channel 368 and otherwise enhance operation. Upon being struck by the barrel foot 344, the latch pin 364 may be configured to retract to the retracted position and subsequently return to the extended position, shown in FIGS. 6A-6B, capturing the barrel foot 344 after the barrel foot 344 overcomes the latch pin 364, securing the barrel assembly 112 in the firing position.

To position the barrel assembly 112 in the loading position, the latch tab 362 may be retracted to move the latch pin 364 to the retracted position and disengage the latch pin 364 from the barrel foot 344. Upon the barrel foot 344 being disengaged from the latch pin 364, a barrel assembly spring 378, shown in FIG. 8., may urge the barrel assembly 112 in an upward direction relative to the firing position of the pistol 100 toward the loading position, exposing the barrel chambers 336 of the barrel assembly 112 for loading ammunition. The barrel assembly spring 378 may be positioned between the receiver 108 and the barrel assembly 112 in any suitable configuration capable of urging the barrel assembly 112 into the loading position as described. In the loading position, the barrel chambers 336 of the barrel assembly 112 may be removed from the breech face 224 in order to expose the barrel chambers 336. In the firing position, the barrel chambers 336 may be positioned substantially adjacent the breech face 224. Further, the barrel assembly 112 may include a barrel hood 382 configured to engage the breech face 224 when the barrel assembly 112 is in the firing position. Similar to the barrel chambers 336, the barrel hood 382 may be removed from the breech face 224 when the barrel assembly 112 is in the loading position.

An optional ejector (not shown) may be coupled to the barrel assembly 112 and configured to urge the ammunition cartridges 222 out of the barrel chambers 336 when the barrel assembly 112 is moved to the loading position. The ejector may be, for example, spring biased in an outward direction from the barrel chambers 336 and configured to engage the ammunition cartridges 222 for extracting the ammunition cartridges 222 from the barrel chambers 336. The ejector may enhance the extraction and reloading of the ammunition cartridges 222 in the barrel assembly 112.

In some embodiments, as shown in FIGS. 1A-1B, the barrel assembly 112 may include a loaded chamber indicator 386 configured to indicate the presence of the ammunition cartridges 222 in the barrel assembly 112. When the barrel assembly 112 is in the firing position, a window 388 may be defined between the barrel chambers 336 and the breech face 224. The window 388 may permit an operator to view the ammunition cartridges 222 being present in the barrel chambers 336 when the pistol 100 is in the firing position. Thus, the loaded chamber indicator 386 may provide enhanced safety.

In some embodiments, as shown in FIGS. 1A-1B, 3, 4, 5A-5B, 6A-6B, and 8, gas ports 390 may be disposed through the wall of each of the first barrel 330 and the second barrel 332. The gas ports 390 may be adapted to vent pressurized gases from within the first barrel 330 and the second barrel 332 to the atmosphere. The pressurized gases may be vented in various directions and angles configured to reduce recoil and muzzle climb of the pistol 100 during fire.

In some embodiments, as shown in FIGS. 1A-6B and 8, the barrel assembly 112 of the pistol 100 may include an integrated, low profile sight 392. The low profile sight 392 may be comprised of a material capable of being perceived by an operator in low light conditions, such as, for example, tritium. For the orientation of FIGS. 1A-1B, the low profile sight 392 may be, for example, a projection extending from the top surface of the barrel assembly 112 proximate the muzzle 338. Further, the low profile sight 392 may be utilized with a rear sighting notch 394. The rear sighting notch 394 may be, for example, a notch or groove machined or otherwise integrally formed into the substrate material of the top surface of the barrel assembly 112 or the receiver 108. The low profile sight 392 may be configured to be perceived by an operator within the rear sighting notch 394 for aiming the pistol 100 during fire.

In some embodiments, as shown in FIGS. 1A-1B, 4, 5A-5B, 6A-6B, and 8, opposing sides of the barrel assembly 112 may include grasping serrations 396. The grasping serrations 396 may be configured to provide an operator with a gripping surface that may assist, for example, with moving the barrel assembly 112 between the loading position and the firing position. The grasping serrations 396 may be, for example, serrations, grooves, notches, or other disturbances that may be machined, cut, or otherwise formed into the substrate material of the barrel assembly 112. The grasping serrations 396 may have any suitable design or pattern, and in some embodiments, may be coupled as a separate component to the barrel assembly 112.

The barrel assembly 112 may be interchangeable with other barrel assemblies capable of firing different calibers of ammunition. For example, the barrel assembly 112 may be chambered or configured for .45 caliber ammunition cartridges and may be removed and replaced with another barrel assembly chambered or configured for 9 mm ammunition cartridges. Further, the barrel assembly 112 may be multi-caliber and configured to fire different calibers of ammunition. In some embodiments, the first barrel 330 of the barrel assembly 112 may be chambered or configured to fire one caliber of ammunition and the second barrel 332 may be chambered or configured to fire another caliber of ammunition. For example, the first barrel 330 may be chambered for .45 caliber ammunition and the second barrel 332 may be chambered for 9 mm ammunition. By way of example and without limitation, barrel assemblies including barrels for available calibers may include .22 caliber, .22 Magnum, .22 Hornet, 5.7×28 mm, .25 caliber, .380 caliber, 9 mm, 10 mm, .40 Smith & Wesson, .38 Special, .357 Magnum, 0.410 gauge, .45 Automatic Colt Pistol, .45 Long Colt, .44 Magnum, .50 Smith & Wesson Magnum, or such other calibers as may be available or desired. The first barrel 330 and the second barrel 332 may include any suitable rifling corresponding to a particular caliber, such as, for example, rifling pursuant to standard SAAMI specifications.

Referring to FIGS. 6A-6B, a latch lock 402 may be disposed in the receiver 108 and may be configured to lock or otherwise secure the latch assembly 360 relative to the barrel assembly 112, for example, during discharge of the pistol 100. The latch lock 402 may momentarily and automatically lock or secure the latch assembly 360 relative to the barrel assembly 112 upon firing the pistol 100. After firing the pistol 100, the latch lock 402 may automatically unlock, permitting the barrel assembly 112 to be released from the latch assembly 360 and moved to the loading position. In some embodiments, the latch lock 402 may be automatically and momentarily locked by operation of the trigger 116 being moved to the refracted position 122. The latch lock 402 may be automatically unlocked by operation of the trigger 116 being moved or otherwise returning to the extended position 120.

The latch lock 402 may include a locking member 406 and an actuating member 410. The locking member 406 and the actuating member 410 may each be slidably positioned within a latch lock channel 414 disposed in the receiver 108. The latch lock channel 414 may be in communication between the guide port 128 for the trigger spring guide 126 and the latch pin channel 368. For example, the locking member 406 and the actuating member 410 may be moveable within the latch lock channel 414 between the guide port 128 and the and the latch pin channel 368. An actuating member stop 418 may be configured to capture and retain the actuating member 410 within the latch lock channel 414. The actuating member stop 418 may be positioned at an end of the latch lock channel 414 proximate the guide port 128, and may be configured to permit a portion of the actuating member 410 to protrude into the guide port 128. Thus, the actuating member 410 may be configured to momentarily engage the trigger spring guide 126 in the guide port 128 upon the trigger 116 being moved from the extended position 120 to the retracted position 122.

The actuating member stop 418 may be, for example, a hole, aperture, or taper that may be formed into or coupled to the latch lock channel 414 having a diameter or size that is less than a diameter or size of the actuating member 410. In this configuration, the actuating member stop 418 may retain the actuating member 410 while permitting a portion of the actuating member 410 to protrude through the actuating member stop 418 into the guide port 128. In other embodiments, the actuating member stop 418 may be any suitable component or combination of components configured to retain the actuating member 410 as described.

The actuating member 410 may be positioned in the latch lock channel 414 between the actuating member stop 418 and the locking member 406. The locking member 406 may be positioned in the latch lock channel 414 between the actuating member 410 and the latch pin channel 368. The actuating member 410 may be configured to impart movement upon the locking member 406 in the latch lock channel 414. For example, the actuating member 410 may be positioned adjacent to or in direct contact with the locking member 406 such that the actuating member 410 and the locking member 406 may be moveable together within the latch lock channel 414. In other embodiments, the actuating member 410 and the locking member 406 may be coupled to one another or otherwise formed as a single component. In some embodiments (not shown), a spring may be positioned in the latch lock channel 414 and configured to bias the locking member 406 and the actuating member 410 toward the actuating member stop 418.

The locking member 406 may be an elongate pin or other longitudinal member, and the actuating member 410 may be a metal ball, ball bearing, or similarly shaped member. Upon the movement of the trigger 116 from the extended position 120 to the retracted position 122, the trigger spring guide 126 may engage the actuating member 410 in the guide port 128 and move the actuating member 410 out of or away from the guide port 128 and toward the latch pin channel 368. The movement of the actuating member 410 away from the guide port 128 toward the latch pin channel 368 may move the locking member 406 toward the latch pin channel 368 in a corresponding manner. An end of the locking member 406 may be positioned to face the latch pin 364 in the latch pin channel 368 and configured to engage the latch pin 364 upon being urged toward the latch pin channel 368. For example, the latch pin 364 may have a locking pocket 420 for receiving the end of the locking member 406 therein when the latch pin 364 is in the extended position. In this configuration, when the latch pin 364 is in the extended position, the locking pocket 420 may be substantially aligned with or concentric to the latch lock channel 368. Thus, when the latch pin 364 is in the extended position and the trigger 116 is moved to the refracted position 122 as described, the trigger spring guide 126 may engage the actuating member 410 and urge the locking member 406 into engagement with the locking pocket 420 in the latch pin 364. Accordingly, such a configuration may permit the latch lock 402 to operate on the latch pin 364 of the latch assembly 360 for momentarily and automatically locking the barrel foot 344 and the barrel assembly 112 in the firing position during discharge of the pistol 100.

Referring to FIGS. 5A-6B and 9A-9D, the receiver 108 of the pistol 100 may include a handle 430 having a cartridge trap 434 configured to store spare ammunition cartridges 438. The spare ammunition cartridges 438 may be accessible in the cartridge trap 434 through a trap door 442, and may be secured in the cartridge trap 434 by a loading clip 446.

The trap door 442 may, for example, be pivotal between a closed position, shown in FIGS. 5A-6B, and an open position, shown in FIGS. 9A-9B. A pivotally coupled end 450 of the trap door 442 may be configured, for example, to accept a pin 454 disposed in or through the handle 430. An opposing end or swinging end 458 of the trap door 442 may carry an adjustable retaining member 460 configured to engage a retaining pocket 464 in the handle 430 for releaseably securing the trap door 442 in the closed position. The trap door 442 may define at least a portion of a butt 466 of the handle 430.

The adjustable retaining member 460 may include a detent housing 470, a ball 474, and a ball biasing spring 478. The detent housing 470 may have a cylindrical shape and a hollow housing bore 480 sized to slidably receive the ball 474 and the ball biasing spring 478 within the housing bore 480. The ball 474 may be captured and retained within the housing bore 480 at an end of the detent housing 470 carrying a crimp 482. The crimp 482 may have a diameter or size that is less than a diameter or size of the ball 474 such that a portion of the ball 474 may protrude through the crimp 482 while being retained by the crimp 482. The ball 474 may be positioned within the housing bore 480 between the ball biasing spring 478 and the crimp 482 such that the biasing spring 478 may be configured to bias the ball 474 toward the crimp 482. The ball 474 may be retractable within the housing bore 480 against the spring bias of the ball biasing spring 478. The detent housing 470 may have a receptor head 484 positioned at an opposite end of the detent housing 470 from the crimp 482. The receptor head 484 may be configured to receive a tool, such as a hand tool, for adjusting the adjustable retaining member 460. For example, the receptor head 484 may have a slotted surface, hex-shaped surface, or any other shape or configuration suitable for engaging the tool. Further, the detent housing 470 may have a cylindrically shaped external surface that may carry external threads 485 configured and sized to be received within an internally threaded bore 486 in the trap door 442.

The threaded bore 486 in the trap door 442 may be positioned at the swinging end 458 of the trap door 442 and disposed through both opposing sides of the swinging end 458. The detent housing 470 may be threadedly inserted into the threaded bore 486 such that the receptor head 484 may be engaged from one side of the swinging end 458 of the trap door 442 and the ball 474 may be exposed at the opposing side of the swinging end 458. Turning the detent housing 470 within the threaded bore 486 may move the detent housing 470 between the opposing sides of the swinging end 458. Thus, the receptor head 484 may be configured to be engaged from one side of the swinging end 458 for moving the ball 474 toward or away from the opposite side of the swinging end 458 to adjust a height of protrusion of the ball 474 from the opposite side.

When the trap door 442 is in the closed position, the ball 474 may be configured to engage the retaining pocket 464 in the handle 430. For example, when the trap door 442 is moved to the closed position, the ball 474 may be configured to retract into the housing bore 480 and subsequently expand into the retaining pocket 464 after being substantially aligned with the retaining pocket 464 in the closed position. Thus, an increase in the height of protrusion of the ball 474 from one side of the swinging end 458 of the trap door 442 may correspond to an increase in tension and retaining force between the ball 474 and the retaining pocket 464. In this manner, the adjustable retaining member 460 may be configured to permit an operator to adjust the amount of force required to move the trap door 442 to the open position for accessing the spare ammunition cartridges 438 and performing a reload.

The loading clip 446 may be configured to secure, for example and without limitation, two of the spare ammunition cartridges 438 in substantially the same configuration and orientation as the positioning of first barrel 330 relative to the second barrel 332. In this manner, the spare ammunition cartridges 438 may be rapidly and simultaneously disposed in the barrel chamber 336 of the first barrel 330 and the barrel chamber 336 of the second barrel 332. Further, the loading clip 446 may be sized to have an interference fit within a cartridge trap channel 490 disposed in the cartridge trap 434 for substantially precluding rattle or other movement of loading clip 446 and the spare ammunition cartridges 438 within the cartridge trap 434. The loading clip 446 may be formed of any suitable material and may have any configuration capable of releaseably securing the spare ammunition cartridges 438 in the loading clip 446. For example, the loading clip 446 may be comprised of a flexible polymer and the spare ammunition cartridges 438 may be pressed into a cartridge cavity 494 in the loading clip 446 and releaseably retained therein by an interference or friction fit. The cartridge cavity 494 may have any suitable configuration, shape, or geometry capable of securing a cartridge head 496 of the spare ammunition cartridges 438 within the cartridge cavity 494 by friction or interference fit.

The loading clip 446 may include a loading tab 498 configured to provide a grasping surface to facilitate expedient retrieval of the spare ammunition cartridges 438 from the cartridge trap 434 and loading of the spare ammunition cartridges 438 into the barrel chambers 336. The loading tab 498 may be coupled to an end of the loading clip 446 configured to be positioned proximate the trap door 442 within the cartridge trap 434 when the trap door 442 is in the closed position. When the trap door 442 is in the closed position as shown in FIGS. 6A-6B, the loading tab 498 may be bent or folded within the cartridge trap 434. However, when the trap door 442 is moved to the open position, the loading tab 498 may be configured to elastically extend from the cartridge trap 434 for retrieval as shown in FIGS. 9A-9B to further enhance expedient loading of the spare ammunition cartridges 438.

In one exemplary embodiment performing a reload for the pistol 100, an operator may retract the latch tab 362 to move the barrel assembly 112 to the loading position for loading the pistol 100 with the spare ammunition cartridges 438. While in the loading position with the barrel chambers 336 cleared of the breech face 224, the operator may remove any previously discharged ammunition cartridges from the barrel chambers 336. The operator may move the trap door 442 to the open position, overcoming the force between the ball 474 of the adjustable retaining member 460 and the retaining pocket 464. The loading clip 446 retaining the spare ammunition cartridges 438 may then be removed from the cartridge trap 434. While holding the loading tab 498, the operator may quickly reload the pistol 100 by tearing the loading clip 446 away from the spare ammunition cartridges 438 after inserting the spare ammunition cartridges 438 into the barrel chambers 336. Subsequently, the operator may move the barrel assembly 112 into the firing position in the receiver 108, engaging the barrel foot 344 with the latch assembly 360 described above.

In some embodiments, the receiver 108 may have additional features. For example, the handle 430 may have a rearward angle, relative to the vertical firing position of the pistol 100, of about 17 degrees. Further, in some embodiments, as shown in FIGS. 5B-6B, the receiver 108, such as the handle 430 of the receiver 108, may include a lanyard loop 502 adapted to provide a securing point for a lanyard (not shown) that may be used for retention of the pistol 100. The lanyard loop 502 may be, for example, an aperture or recessed cross-pin configured to accept a lanyard (not shown) in the form of a rope, chain, or other retention device. The lanyard loop 502 may be substantially flush fitting and snag-free relative to the receiver 108. Other embodiments of the lanyard loop 502 may include a ring-shaped device coupled to the receiver 108 for securing a lanyard thereto.

In some embodiments, as shown in FIGS. 1A-1B, 5A-5B, and 8-9B, the handle 430 of the pistol 100 may include an integral gripping surface 506. The integral gripping surface 506 may be, for example, machined, cut, cast, or otherwise formed into the substrate material or surface of the handle 430. The integral gripping surface 506 may enhance the ability of the pistol 100 to retain a slim, snag-free design. The integral gripping surface 506 may have any suitable texture for providing friction between the hand of an operator and the handle 430 of the pistol 100. For example, the gripping surface 430 may comprise a plurality of depressions 508 and protrusions 510 adapted to engage the hand of an operator. In some embodiments, the gripping surface 506 may include a fragmentation grenade pattern.

In some embodiments, the pistol 100 may be adapted to operate with accessories such as, for example, a laser sighting device or a light (not shown). An accessory mount (not shown) such as, for example, a standard picatinny rail or similar device may be secured to the pistol 100, or formed integrally into the pistol 100, and sized to accept a desired accessory.

Components such as the first hammer actuation cam 150, the second hammer actuation cam 152, the drive cam 154, the trigger link 132, the first internal hammer 180, and the second internal hammer 182 may be, for example, comprised of 17-4 ph stainless steel. The receiver 108 of the pistol 100 may be comprised of various materials, including without limitation polymer, 7075 aluminum, and 6AL-4V titanium. Further, the first firing pin 184 and the second firing pin 186 may, without limitation, be comprised of 6AL-4V titanium, other grades of titanium, or other materials. The use of titanium for the first firing pin 184 and the second firing pin 186 may reduce inertia for enhancing safety and reliability. For example, with less inertia, the first firing pin 184 and the second firing pin 186 may be driven at higher velocity for improved ignition of the ammunition cartridges 222. Further, having less inertia, the first firing pin 184 and the second firing pin 186 may be less prone to accidental discharges for increased safety. The above materials may have sufficient strength to permit the pistol 100 to have a compact size. For example, the pistol 100 may have a width of less than or equal to about 0.665 inches, a length of less than or equal to about 5.5 inches, a height of less than or equal to about 3.9 inches, and a weight between about 8 ounces to about 20 ounces. For example, the weight may be about 8 ounces, about 9 ounces, about 10 ounces, about 11 ounces, about 12 ounces, about 13 ounces, about 14 ounces, about 15 ounces, about 16 ounces, about 17 ounces, about 18 ounces, about 19 ounces, or about 20 ounces. The first barrel 330 and the second barrel 332 may each be about 3.0 inches long. Other materials such as scandium, polymers, various metals, and metal alloys may be used interchangeably for the components of the pistol 100 without limitation.

Further, surfaces of the pistol 100 may include a variety of coatings or finishes for preventing, for example, corrosion, friction, and glare. Aluminum components of the pistol 100 may, for example, include a Type III hard-anodizing per military specifications. Titanium components of the pistol 100 may, for example, include a coating designated under the trade name CERAKOTE by Cerakote Firearm Coatings of White City, Oreg., United States (www.cerakoteguncoatings.com). Stainless steel components of the pistol 100 may, for example, include a black nitride or other coating. The above described coatings for the pistol 100 are provided without limitation and may be interchangeable among the various components and materials comprising the pistol 100.

Although this detailed description discloses certain illustrative, non-limiting embodiments, various changes, substitutions, permutations, and alterations may be made without departing from the scope of this description as defined by the appended claims. For example, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and configurations will depend upon the specific application or applications for which the disclosed teachings are used. Further, any feature described in connection with any one embodiment may also be applicable to any other embodiment.

Additionally, the technology described herein may be embodied as a method of which at least one example has been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, the embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in an illustrative embodiment. 

What is claimed is:
 1. A firearm, comprising: a receiver; a barrel assembly comprising a first barrel and a second barrel; a trigger moveable between an extended position and a retracted position; a first hammer configured to strike a first firing pin with a first movement of the trigger from the extended position to the retracted position; and a second hammer configured to strike a second firing pin with a second movement of the trigger from the extended position to the retracted position.
 2. The firearm of claim 1, further comprising a handle and a cartridge trap disposed within the handle, the cartridge trap being configured to receive at least one spare ammunition cartridge.
 3. The firearm of claim 2, wherein the cartridge trap is accessible through a trap door pivotally secured to the handle.
 4. The firearm of claim 2, wherein the cartridge trap is configured to receive a loading clip, the loading clip being configured to releaseably secure the spare ammunition cartridge relative to another spare ammunition cartridge.
 5. The firearm of claim 1, further comprising a handle and an integral gripping surface disposed in a substrate material of the handle.
 6. The firearm of claim 1, further comprising a lanyard loop.
 7. The firearm of claim 1, wherein the receiver has a width of 0.0665 inches or less.
 8. The firearm of claim 1, wherein the barrel assembly is configured to pivot relative to the receiver between a loading position and a firing position.
 9. The firearm of claim 8, wherein the first barrel and the second barrel each include a barrel chamber, the barrel chamber of each of the first barrel and the second barrel being removed from a breech face of the receiver in the loading position and adjacent the breech face in the firing position.
 10. The firearm of claim 1, wherein the barrel assembly further comprises a barrel lug having a lug aperture configured to slidably accept a pivot pin disposed in the receiver, wherein the barrel assembly is pivotal about the pivot pin relative to the receiver between a loading position and a firing position.
 11. The firearm of claim 10, wherein the pivot pin is retractable from the receiver and the barrel lug for disengaging the barrel assembly from the receiver.
 12. The firearm of claim 1, wherein the barrel assembly includes a barrel foot configured to releasably engage a latch assembly positioned in the receiver when the barrel assembly is in a firing position, the barrel foot being disengaged from the latch assembly when the barrel assembly is in a loading position.
 13. The firearm of claim 1, wherein the barrel assembly further comprises grasping serrations disposed on opposing sides of the barrel assembly.
 14. The firearm of claim 1, wherein the barrel assembly further comprises a barrel hood configured to engage a breech face of the receiver when the barrel assembly is in a firing position, the barrel hood being disengaged from the breech face when the barrel assembly is in a loading position.
 15. The firearm of claim 1, further comprising a loaded chamber indicator including a window defined between a breech face of the receiver and a barrel chamber of each of the first barrel and the second barrel when the barrel assembly is in a firing position.
 16. The firearm of claim 1, wherein at least one of the first and the second barrel is configured to fire ammunition cartridges selected from the group consisting of: .22 caliber, .22 Magnum, .22 Hornet, 5.7×28 mm, .25 caliber, .380 caliber, 9 mm, 10 mm, .40 Smith & Wesson, .38 Special, .357 Magnum, .410 gauge, .45 Automatic Colt Pistol, .45 Long Colt, .44 Magnum, and .50 Smith & Wesson Magnum.
 17. The firearm of claim 1, further comprising a first hammer actuation cam and a second hammer actuation cam, the first hammer actuation cam being rotatable relative to the receiver and having a plurality of first lobes spaced at a first degree of separation, and the second hammer actuation cam being rotatable relative to the receiver and having a plurality of second lobes spaced at a second degree of separation.
 18. The firearm of claim 17, wherein the first degree of separation is substantially equidistant between each of the first lobes, and wherein the second degree of separation is substantially equidistant between each of the second lobes.
 19. The firearm of claim 17, wherein the second degree of separation substantially corresponds to the first degree of separation.
 20. The firearm of claim 17, wherein the second lobes are secured in a fixed position relative to the first lobes at substantially one-half of the first degree of separation.
 21. The firearm of claim 17, further comprising a drive cam rotatable relative to the receiver and secured in a fixed position relative to the first hammer actuation cam and the second hammer actuation cam, the drive cam comprising a plurality of teeth disposed about the drive cam, one of the teeth being positioned substantially with zero degrees of separation relative to each of the first lobes and each of the second lobes.
 22. The firearm of claim 17, wherein the first hammer comprises a first hammer foot configured to move from a first position engaged with one of the first lobes to a second position disengaged from the first lobe in the first movement of the trigger, and wherein the second hammer comprises a second hammer foot configured to move from a first position engaged with one of the second lobes to a second position disengaged from the second lobe in the second movement of the trigger.
 23. The firearm of claim 22, wherein the first hammer has a first free end pivotal about a first secured end, the first free end having a first hammer face configured to strike the first firing pin, wherein the second hammer has a second free end pivotal about a second secured end, the second free end having a second hammer face configured to strike the second firing pin, and wherein the first hammer foot is positioned at the first secured end and the second hammer foot is positioned at the second secured end.
 24. The firearm of claim 17, wherein the trigger is configured to rotate each of the first hammer actuation cam and the second hammer actuation cam relative to the receiver when the trigger moves from the extended position to the retracted position.
 25. The firearm of claim 21, further comprising a pawl coupled to the trigger and moveable with the trigger from the extended position to the retracted position, wherein pawl is configured to engage the teeth on the drive cam for rotating the first hammer actuation cam and the second hammer actuation cam.
 26. The firearm of claim 1, wherein the first firing pin is positioned in a breech face of the receiver and configured to fire the first barrel, and wherein the second firing pin is positioned in the breech face and configured to fire the second barrel.
 27. A firing system, comprising: a camshaft; a first hammer actuation cam rotatable about the camshaft, the first hammer actuation cam comprising a plurality of first lobes spaced at a first degree of separation that is substantially equidistant between each of the first lobes; a second hammer actuation cam rotatable about the camshaft, the second hammer actuation cam comprising a plurality of second lobes spaced at a second degree of separation that is substantially equidistant between each of the second lobes; a drive cam rotatable about the camshaft, the drive cam disposed between the first hammer actuation cam and the second hammer actuation cam; wherein the drive cam is secured in a fixed position relative to the first and the second hammer actuation cam, and wherein the drive cam comprises a plurality of teeth disposed about the drive cam, one of the teeth on the drive cam being positioned substantially with zero degrees of separation relative to each of the first lobes and each of the second lobes; a first hammer adapted to pivot about a fulcrum, the first hammer comprising a first hammer foot adapted to engage the first lobes; and a second hammer adapted to pivot about the fulcrum, the second hammer comprising a second hammer foot adapted to engage the second lobes.
 28. The firing system of claim 27, wherein the second degree of separation substantially corresponds to the first degree of separation.
 29. The firing system of claim 27, wherein the second lobes are secured in a fixed position relative to the first lobes at substantially one-half of the first degree of separation.
 30. The firing system of claim 27, wherein the second degree of separation substantially corresponds to the first degree of separation and the second lobes are secured in a fixed position relative to the first lobes at substantially one-half of the first and the second degree of separation.
 31. The firing system of any of claim 27 to claim 30, further comprising: a trigger; and a pawl coupled to the trigger, the pawl adapted to engage the plurality of teeth disposed on the drive cam.
 32. The firing system of any of claim 27 to claim 30, further comprising: a trigger; and a pawl coupled to the trigger, wherein the pawl is configured to engage the drive cam and rotate each of the first and the second hammer actuation cams about the camshaft when the trigger moves from a first position to a second position.
 33. A firearm, comprising: a plurality of barrels; and a double-action firing system comprising a trigger moveable between an extended position and a retracted position, wherein the double-action firing system is configured to fire one of the barrels with a first movement of the trigger from the extended position to the retracted position and another of the barrels with a second movement of the trigger from the extended position to the retracted position. 